Tanker War

The Tanker War, part of the larger Iran–Iraq War, was a series of military attacks by Iran and Iraq against merchant vessels in the Persian Gulf and Strait of Hormuz from 1984 to 1988.

History
Before 1984, attacks against shipping had occurred, albeit on a much smaller scale. In December 1980, UN Secretary General Kurt Waldheim appealed to Iran and Iraq to ensure the security of peaceful shipping in the Gulf. At that time, Iran assured other countries that it would keep the Strait of Hormuz open.

Iraq launched the Tanker War in 1984 by attacking the oil terminal and oil tankers at Kharg Island. Iraq's aim in attacking Iranian shipping was to provoke the Iranians to retaliate with extreme measures, such as closing the Strait of Hormuz to all maritime traffic, thereby bringing about foreign intervention against Iran; the United States had threatened several times to intervene if the Strait of Hormuz were closed. Kuwait and Saudi Arabia supported Iraq against Iran. The United States intervened in the conflict in 1986 to protect Kuwaiti tankers, and engaged in a confrontation with Iran.

Both sides had declared an "exclusion zone", meaning areas in which they had warned ships from entering. Iraq declared the area around Iran's Kharg Island to be an exclusion zone. Kharg Island hosted Iran's principal oil shipment port. Iraq gave precise definition, in coordinates, of this exclusion zone and gave advance notification to all countries. However, Iraq did not designate any safe passage routes in this zone.

Iran declared all waters within 40 miles of its coast to be its exclusion zone. It instructed ships headed for non-Iranian ports to sail west of this line. While Iran also did not designate any safe passages in its exclusion zone, this was unnecessary. Iran's exclusion zone allowed for ships to enter and exit the Gulf, and essentially only kept such foreign ships out of its own waters.

Ironically, Iran's exclusion zone made it easier for Iraq to target Iranian ships. It allowed Iraq to assume that any ship in Iran's territorial waters must be going to (or coming from) an Iranian port.

United Nations Security Council Resolution 598, was adopted unanimously on 20 July 1987, which engendered Operation Earnest Will (24 July 1987 – 26 September 1988), a successful United States effort to protect Kuwaiti merchandise and vessels. There were 37 US sailors killed by an Iraqi attack on the USS Stark.